This invention relates to an outlet air diffuser for use with climate control systems such as a roof mounted heating, ventilating and air conditioning systems for supplying air to a space in a building within which the climate is controlled by the system, and more particularly to a multiport outlet diffuser receiving conditioned air from a duct and directing it into the space and a method for manufacturing the diffuser.
Climate control systems used in heating, ventilating and air conditioning systems (HVAC systems) are often utilized in buildings to provide a desired climate within a space in the building. In buildings of a commercial nature, such as warehouse-type retail stores, the climate control units are often mounted on the roof and at least one duct typically extends downwardly from the units through the roof. In these constructions, the duct, or ducts, within the building comprise a plenum which connects the climate control unit to a diffuser. The plenum communicates air between the inlet of the air diffuser and the outlet of the climate control unit. Diffusers often have ports which extend in various directions to efficiently direct the air to various locations within the building in which the diffuser is located. See FIGS. 1 and 3-5 for prior art diffuser designs. FIG. 2 is a prior art diffuser insert.
Some buildings utilize structures, known as roof curbs, which are typically installed with the roof during roof construction. The roof curb may become a permanent part of the roof. Typically, a climate control unit is positioned and/or connected above the curb and connects with the plenum to a diffuser or the climate control unit.
Traditionally, the outlets of the HVAC climate control equipment are rectangular in configuration. It is believed that this rectangular configuration is a result of manufacturers' attempts to provide air flow through a pair of roofjoints. Additionally, the openings within roof curbs which receive the outlet air from an HVAC unit are similarly rectangular in nature, as shown in FIG. 6D. Furthermore, the inlet to prior art diffusers are typically square. Accordingly, the prior art transition ducts, in addition to providing a plenum, also transition from the rectangular outlet of the HVAC unit to the square inlet of the diffuser as illustrated in FIGS. 6A-6C.
Typically, in the prior art a pair of trancissions, or transition ducts, have been provided between the outlet of the roof curb and the inlet of the diffuser plenum. Also in the prior art, the transition duct is typically connected to a roof curb by removing one side of a removable side portion of a roof curb, positioning the transition duct from below, reinstalling the removable side and bolting the transition duct to the roof curb from the top of the roof. Next, the diffuser will be installed to the transition duct, also from below. The prior art construction techniques require the connection at least two different interfaces all from within the building at an elevation above floor level. This process is labor and time intensive.
In the traditional construction technique, the rectangular shape of the opening through the roof curb has a longer length than width. The square sides of the diffuser inlet are longer than the narrow width of the curb opening. Accordingly, the transition duct could not be installed from the top as the cross-sectional area of the portion which mates with the diffuser would not fit through the curb opening if one attempted to position it through the roof on the top. This necessitated the removal of a side of the curb.
At least one manufacturer has developed a plenum of substantially square dimensions and an appropriate roof curb having square dimensions such that the square connecting duct may be installed from the top of the roof directly through the roof curb and bolted into place from the top of the roof as illustrated in FIG. 7. Then, the only connection which needs to be made within the building is connecting the diffuser to the bottom of the connecting duct. In this construction technique, however, it is believed that additional ductwork will be necessary above the roof curb to connect the curb to the outlet of an HVAC unit having a rectangular outlet. Accordingly a need exists to connect a traditional HVAC outlet to the traditional roof curb along with a diffuser where much of the installation may be performed from at or above the roof.